As used herein, the term “organic electronic device” refers to a device that requires the exchange of an electronic charge between an electrode and an organic material using holes and/or electrons. The organic electronic device can be largely classified according to its operational principle into two types as follows. One type is an electronic device having a configuration in which an exciton is formed in an organic material layer by the entry of photons into the device from an external light source, and is then separated into an electron and a hole, which are transferred to different electrodes as a current source (voltage source), and the other type is an electric device having a configuration in which a voltage or a current is applied to two or more electrodes to inject a hole and/or an electron into an organic semiconductor positioned at the interface between the electrodes, and the device is operated using the injected electron and hole.
Examples of the organic electronic device include an organic light-emitting device, an organic solar cell, an organic transistor and the like, all of which require a hole-injecting or hole-transporting material, an electron-injecting or electron-transporting material or a light emitting material to drive the device. Hereinafter, the organic light-emitting device will be mainly and specifically described, but in the above-mentioned organic electronic devices, the hole-injecting or hole-transporting material, the electron-injecting or electron-transporting material, or the light-emitting material injection functions according to a similar principle.
In general, the term “organic light-emitting phenomenon” refers to a phenomenon in which electric energy is converted to light energy using an organic material. The organic light-emitting device that uses the organic light-emitting phenomenon usually has a structure comprising an anode, a cathode and an organic material layer interposed therebetween. Herein, the organic layer often has a multilayer structure consisting of a plurality of layers made of different materials in order to increase the efficiency and stability of the organic light-emitting device. For example, the organic material layer may consist of a hole-injecting layer, a hole-transporting layer, a light-emitting layer, an electron-transporting layer, an electron-injecting layer and the like. In the organic-light emitting device having this structure, when a voltage is applied between two electrodes, holes from the anode and electrons from the cathode are injected into the organic material layer, and the injected holes and electrons are combined with each other to form excitons. When the excitons subsequently drop to the ground state, light is emitted.
The development of novel materials for organic light-emitting devices as described above has been continuously demanded, and the development of materials for other organic electronic devices as described above has also been demanded.